In his second State of the Union address, set to start at 9 p.m. Tuesday, all Mr. Obama needs to do is keep the momentum going, political analysts say. He has rebounded in public opinion after a productive lame-duck session of Congress and then a moving speech in Tucson, Ariz., that played on popular themes: civility, national unity, and common ground.

Still, he adds, that may be easier said than done – and in steering down a more centrist path, he could both inflame the right wing and alienate his liberal base. The president, Obama advisers have said, will describe five “pillars” for “winning the future” – education, infrastructure, innovation, deficit reduction, and reform of government.

Obama is also expected to endorse a ban on congressional earmarks, a five-year freeze in nonsecurity discretionary spending, and $78 billion in savings on defense – all in the name of getting America’s “fiscal house in order.” But it’s not clear whether he will get specific about the biggest driver of the nation’s debt and deficits – skyrocketing health-care costs and the entitlement programs affected by that, Medicare and Medicaid.

“In a couple of weeks, the president is going to be putting forth a budget that will articulate very clearly where we want to go in the future,” Ms. Barnes said Tuesday on MSNBC. “It will be a balance of the right investments of the kind that I just talked about and, also, dealing with our deficit spending in a very serious way.”

When the president’s bipartisan deficit commission issued its recommendations late last year, Obama did not respond to specifics but promised to have his new budget director, Jacob Lew, talk to commission members and figure out which elements should be incorporated into future government plans.

The commission’s proposed cuts in Medicare and Social Security were a particular source of concern for progressives, who worry that deficit reduction will take place on the backs of those who can least afford it.

So far, both parties have steered clear of embracing particulars. The Republicans have put forth Rep. Paul Ryan (R) of Wisconsin, new chairman of the House Budget Committee, to deliver the GOP response to the State of the Union. Representative Ryan is a rising Republican star best known for his “road map” that calls for dramatic reconfiguration of entitlements. But the Republican Party has yet to embrace his ideas as its own.

Just as Obama was handed an opportunity – albeit one born of tragedy – when he addressed an arenaful of people in Tucson after the Jan. 8 shootings, so too is the State of the Union an opportunity. Once again, Obama is center stage, a commanding presence.

In the House gallery Tuesday night, Obama will face a much larger, more empowered Republican caucus than he did last year, but he’s still president.

“This is a chance for him to lay out in his own terms what he wants to do,” says John Green, a political scientist at the University of Akron in Ohio. “One of the key political issues is how much of an olive branch does he extend to the Republicans – and how clear of a line does he draw.”

Republicans are expected to point out that all the talk of “investments” is really code for “spending.” But even the deficit commission saw the need for continued spending in education, research and development, and infrastructure, even as other programs are reduced or eliminated.